1. Field of the Invention
The present invention relates generally to a method for making a sour cream type product having the appearance, taste, consistency and texture of sour cream and, more specifically, to a method for making an imitation sour cream product which may be carried out in significantly less time than previously known methods and results in a sour cream type product significantly lower in fat and calories than with previously known methods.
2. Description of the Prior Art
Commercial sour cream, which is a popular ingredient in salad dressings, dips, fillings and like food products, is typically prepared by innoculating pasteurized, homogenized cream having a fat content of about 18% by weight with one or more strains of a lactic acid producing bacterial culture, ripening the cultured cream for about 14 hours at about 70.degree. F., and cooling and packaging the resulting product. Although this method results in a highly acceptable product with a pleasing taste, sour cream prepared according to this method is high in both fat and calories; hence, those who must restrict their intake of fat and/or calories must either severely limit or cease altogether their intake of sour cream and sour cream--containing products. Imitation sour cream products which contain no dairy butterfat are disclosed, for example, in U.S. Pat. No. Re. 27,381. However, these products contain other fats and oils, usually at a level of from 8% to 25% by weight of the product, and therefore are not sufficiently low in either calories or fat.
Another drawback to the conventional method of making sour cream lies in the amount of time required for incubation of the bacterial cultures which produce the lactic acid responsible for the characteristic cultured taste in the finished sour cream product. Efforts have been made to circumvent this time consuming process by the direct acid method which involves adding acid directly to the cream or other equivalent dairy or non-dairy starting materials. Exemplary direct acid methods are disclosed in U.S. Pat. Nos. 3,355,298; 3,359,116; 3,378,375; 3,432,306; 3,506,663; 3,726,690 and Re. 27,381. The majority of these processes, however, either take several hours of processing time or result in a product with a higher fat content than desirable or both. In some, additional chemical additives or processing stages are required to even approach a high quality sour cream type product such as is made by biological fermentation. For example, U.S. Pat. No. 3,359,116 discloses a low calorie sour cream product produced by replacing the butterfat in the milk base starting material with at least 0.5% and up to 25% by weight of a lipoid substance and incorporating a suitable monoglyceride as an acid stabilizing and body building agent. By way of further example, U.S. Pat. No. Re. 27,381 discloses a method for making an imitation sour cream product which can be practiced in about an hour, but which requires inclusion in the product of 8% to 25% by weight of a suitable fat.
U.S. Pat. No. 3,235,387 to Stumbo is illustrative of current methods for the production of sour cream products which utilize acid-producing bacterial cultures. Although the use of stabilizers in these current methods results in an improved product over that achieved by earlier methods using bacterial cultures, processing time is still necessarily quite lengthy since the cultured cream mixture must be allowed to incubate for about 14 hours. In addition, the resulting sour cream product is high in both fat and calories, since the required starting material is cream standardized to 18% to 25% by weight fat. Pavey et al. disclose a method of making a low fat, shelf stable biologically fermented sour cream type product in U.S. Pat. No. 3,969,534. Although Pavey et al. uses a dairy base starting material with a butterfat content of 0% to 5% by weight, the processing of this dairy material to achieve the desired end product, requires considerable time and involves a multiplicity of process steps. For example, the dairy base starting material is homogenized, pasteurized, cooled to incubation temperature, innoculated with culture and allowed to stand for about 4 hours, after which stabilizers are mixed in and a second heating step is carried out for a time sufficient to produce syneresis. The mixture is then homogenized, flavors are added, the acidity is adjusted and the final product is packaged and specially processed to render it stable without refrigeration.